Babies born in the cities at the heart of the US and UK's bloodiest military campaigns in Iraq are more likely to have heart defects, deformed limbs and brain damage, according to a new report.

In the survey, more than half of all babies who were conceived after the US invasion of Fallujah were born with birth defects. Before the siege, it was one in 10.

Graphic images of babies with twisted limbs, organs forming on the outside of bodies and inflated skulls are included in the study funded by the Department of Obstetrics and Gynecology at the University of Michigan.

A mother tends her baby in an Iraqi refugee camp, near Fallujah

Weaponry used by the US in Fallujah and UK forces in Basra has left a "footprint of metal" on the population, and been connected to a disturbing rise in birth defects and miscarriages in those cities, which was published in the Bulletin of Environmental Contamination and Toxicology last month.

In Basra’s Maternity Hospital, birth defects increased by more than 60% in the past seven years, linked by the report's authors to an increased exposure to metals released by the bombs and bullets used over the past decade, including lead and mercury.

The World Health Organisation has also been probing the effect on babies and families of toxic substances used in the bombardment of the city, where hundreds of Iraqis died.

The WHO report into birth defects in Iraq is due next month, but is expected to show a startling increase in deformities in babies born after the Iraq War.

In the study, headed by Mozhgan Savabieasfahani, researchers found that between 2007 and 2010 in Fallujah, more than half of all babies monitored by researchers were born with birth defects.

Before the war, this figure was around one in 10.

More than 45% of all pregnancies surveyed ended in miscarriage in 2005 and 2006, compared to only 10% before the invasion, although mothers experiencing traumatic stress during the invasion could also have been more likely to miscarry.

The most common abnormalities found in the children of Fallujah are congenital heart defects; 24 out of 26 children were born with the defect.

Also common are neural tube defects, which affect 18 out of 46 children, which can result in spina bifida.

Families continuing to leaving Basra in southern Iraq, across bridges manned by British soldiers

Hair samples taken from the population of Fallujah revealed levels of lead in children with birth defects five times higher than in other children, and mercury levels six times higher.

Basra children with birth defects had three times more lead in their teeth than children living in areas of Iraq which were not subject to similar bombardments.

"All ammunition used by UK armed forces falls within international humanitarian law and is consistent with the Geneva Convention," they said.

American forces bombed Fallujah in April 2004, and again seven months later in some of the heavy air strike campaigns seen during the iraq offensive.

The US military has denied they used depleted uranium, which has been repeatedly linked to birth defects.

Other damaging metals include lead and mercury. Lead can pass from mother to child and cause acute lead poisoning, leading to brain and nerve damage.

Ten-day-old Iraqi boy, Wizan, is kept in an incubator as he suffers from post-brith intestinal problems at Basra's infants hospital

Babies who survive lead poisoning may be severely brain damaged or suffer behavioural disorders.

Mercury poisoning damages the brain and kidneys, and the metal can be absorbed through air, water and soil by mothers, who may have babies who suffer blindness, seizures and brain damage.

The WHO has pinpointed nine areas of Iraq, including Fallujah and Basrah, where residents are deemed to be "high risk" for its forthcoming study.

Professor Alastair Hay, a professor of environmental toxicology at Leeds University, who studied the links between Agent Orange on Vietnamese birth defects after the US conflict, called the figures "quite extraordinary, the change seems huge."

He told The Huffington Post UK there had never been a comparable study. "The first thing I would want to do is compare the levels of metals found in people in comparable conflicts worldwide.

"What cannot be discounted is the effects of extreme stress on people living under daily bombardment.

"Stress has major physiological effects, not only miscarriages, but stress can dramatically effect the blood brain barrier, which prevents chemicals in circulation in your body from entering the brain. It is more like to 'leak'. Stress hormones can also cause damage.

"It also matters what the data is like pre-conflict on things like birth defects, which may have been underreported due to social stigma.

"The WHO research will be crucial because it focuses on nine different areas, not just Fallujah and Basrah. This will give a degree of comparability, looking at what weapons were used where and what effects have been seen.

"We need to know a lot more about the affects of conflicts on public health."